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[mirror_ubuntu-artful-kernel.git] / drivers / rtc / rtc-88pm860x.c
1 /*
2 * Real Time Clock driver for Marvell 88PM860x PMIC
3 *
4 * Copyright (c) 2010 Marvell International Ltd.
5 * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 #include <linux/mutex.h>
18 #include <linux/rtc.h>
19 #include <linux/delay.h>
20 #include <linux/mfd/core.h>
21 #include <linux/mfd/88pm860x.h>
22
23 #define VRTC_CALIBRATION
24
25 struct pm860x_rtc_info {
26 struct pm860x_chip *chip;
27 struct i2c_client *i2c;
28 struct rtc_device *rtc_dev;
29 struct device *dev;
30 struct delayed_work calib_work;
31
32 int irq;
33 int vrtc;
34 int (*sync)(unsigned int ticks);
35 };
36
37 #define REG_VRTC_MEAS1 0x7D
38
39 #define REG0_ADDR 0xB0
40 #define REG1_ADDR 0xB2
41 #define REG2_ADDR 0xB4
42 #define REG3_ADDR 0xB6
43
44 #define REG0_DATA 0xB1
45 #define REG1_DATA 0xB3
46 #define REG2_DATA 0xB5
47 #define REG3_DATA 0xB7
48
49 /* bit definitions of Measurement Enable Register 2 (0x51) */
50 #define MEAS2_VRTC (1 << 0)
51
52 /* bit definitions of RTC Register 1 (0xA0) */
53 #define ALARM_EN (1 << 3)
54 #define ALARM_WAKEUP (1 << 4)
55 #define ALARM (1 << 5)
56 #define RTC1_USE_XO (1 << 7)
57
58 #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */
59
60 static irqreturn_t rtc_update_handler(int irq, void *data)
61 {
62 struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
63 int mask;
64
65 mask = ALARM | ALARM_WAKEUP;
66 pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
67 rtc_update_irq(info->rtc_dev, 1, RTC_AF);
68 return IRQ_HANDLED;
69 }
70
71 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
72 {
73 struct pm860x_rtc_info *info = dev_get_drvdata(dev);
74
75 if (enabled)
76 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
77 else
78 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
79 return 0;
80 }
81
82 /*
83 * Calculate the next alarm time given the requested alarm time mask
84 * and the current time.
85 */
86 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
87 struct rtc_time *alrm)
88 {
89 unsigned long next_time;
90 unsigned long now_time;
91
92 next->tm_year = now->tm_year;
93 next->tm_mon = now->tm_mon;
94 next->tm_mday = now->tm_mday;
95 next->tm_hour = alrm->tm_hour;
96 next->tm_min = alrm->tm_min;
97 next->tm_sec = alrm->tm_sec;
98
99 rtc_tm_to_time(now, &now_time);
100 rtc_tm_to_time(next, &next_time);
101
102 if (next_time < now_time) {
103 /* Advance one day */
104 next_time += 60 * 60 * 24;
105 rtc_time_to_tm(next_time, next);
106 }
107 }
108
109 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
110 {
111 struct pm860x_rtc_info *info = dev_get_drvdata(dev);
112 unsigned char buf[8];
113 unsigned long ticks, base, data;
114
115 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
116 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
117 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
118 base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
119
120 /* load 32-bit read-only counter */
121 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
122 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
123 ticks = base + data;
124 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
125 base, data, ticks);
126
127 rtc_time_to_tm(ticks, tm);
128
129 return 0;
130 }
131
132 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
133 {
134 struct pm860x_rtc_info *info = dev_get_drvdata(dev);
135 unsigned char buf[4];
136 unsigned long ticks, base, data;
137
138 if ((tm->tm_year < 70) || (tm->tm_year > 138)) {
139 dev_dbg(info->dev, "Set time %d out of range. "
140 "Please set time between 1970 to 2038.\n",
141 1900 + tm->tm_year);
142 return -EINVAL;
143 }
144 rtc_tm_to_time(tm, &ticks);
145
146 /* load 32-bit read-only counter */
147 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
148 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
149 base = ticks - data;
150 dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
151 base, data, ticks);
152
153 pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
154 pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
155 pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
156 pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
157
158 if (info->sync)
159 info->sync(ticks);
160 return 0;
161 }
162
163 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
164 {
165 struct pm860x_rtc_info *info = dev_get_drvdata(dev);
166 unsigned char buf[8];
167 unsigned long ticks, base, data;
168 int ret;
169
170 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
171 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
172 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
173 base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
174
175 pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
176 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
177 ticks = base + data;
178 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
179 base, data, ticks);
180
181 rtc_time_to_tm(ticks, &alrm->time);
182 ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
183 alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
184 alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
185 return 0;
186 }
187
188 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
189 {
190 struct pm860x_rtc_info *info = dev_get_drvdata(dev);
191 struct rtc_time now_tm, alarm_tm;
192 unsigned long ticks, base, data;
193 unsigned char buf[8];
194 int mask;
195
196 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
197
198 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
199 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
200 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
201 base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
202
203 /* load 32-bit read-only counter */
204 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
205 data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
206 ticks = base + data;
207 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
208 base, data, ticks);
209
210 rtc_time_to_tm(ticks, &now_tm);
211 rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
212 /* get new ticks for alarm in 24 hours */
213 rtc_tm_to_time(&alarm_tm, &ticks);
214 data = ticks - base;
215
216 buf[0] = data & 0xff;
217 buf[1] = (data >> 8) & 0xff;
218 buf[2] = (data >> 16) & 0xff;
219 buf[3] = (data >> 24) & 0xff;
220 pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
221 if (alrm->enabled) {
222 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
223 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
224 } else {
225 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
226 pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
227 ALARM | ALARM_WAKEUP);
228 }
229 return 0;
230 }
231
232 static const struct rtc_class_ops pm860x_rtc_ops = {
233 .read_time = pm860x_rtc_read_time,
234 .set_time = pm860x_rtc_set_time,
235 .read_alarm = pm860x_rtc_read_alarm,
236 .set_alarm = pm860x_rtc_set_alarm,
237 .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
238 };
239
240 #ifdef VRTC_CALIBRATION
241 static void calibrate_vrtc_work(struct work_struct *work)
242 {
243 struct pm860x_rtc_info *info = container_of(work,
244 struct pm860x_rtc_info, calib_work.work);
245 unsigned char buf[2];
246 unsigned int sum, data, mean, vrtc_set;
247 int i;
248
249 for (i = 0, sum = 0; i < 16; i++) {
250 msleep(100);
251 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
252 data = (buf[0] << 4) | buf[1];
253 data = (data * 5400) >> 12; /* convert to mv */
254 sum += data;
255 }
256 mean = sum >> 4;
257 vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
258 dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
259
260 sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
261 data = sum & 0x3;
262 if ((mean + 200) < vrtc_set) {
263 /* try higher voltage */
264 if (++data == 4)
265 goto out;
266 data = (sum & 0xf8) | (data & 0x3);
267 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
268 } else if ((mean - 200) > vrtc_set) {
269 /* try lower voltage */
270 if (data-- == 0)
271 goto out;
272 data = (sum & 0xf8) | (data & 0x3);
273 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
274 } else
275 goto out;
276 dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
277 /* trigger next calibration since VRTC is updated */
278 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
279 return;
280 out:
281 /* disable measurement */
282 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
283 dev_dbg(info->dev, "finish VRTC calibration\n");
284 return;
285 }
286 #endif
287
288 #ifdef CONFIG_OF
289 static int pm860x_rtc_dt_init(struct platform_device *pdev,
290 struct pm860x_rtc_info *info)
291 {
292 struct device_node *np = pdev->dev.parent->of_node;
293 int ret;
294 if (!np)
295 return -ENODEV;
296 np = of_get_child_by_name(np, "rtc");
297 if (!np) {
298 dev_err(&pdev->dev, "failed to find rtc node\n");
299 return -ENODEV;
300 }
301 ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
302 if (ret)
303 info->vrtc = 0;
304 of_node_put(np);
305 return 0;
306 }
307 #else
308 #define pm860x_rtc_dt_init(x, y) (-1)
309 #endif
310
311 static int pm860x_rtc_probe(struct platform_device *pdev)
312 {
313 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
314 struct pm860x_rtc_pdata *pdata = NULL;
315 struct pm860x_rtc_info *info;
316 struct rtc_time tm;
317 unsigned long ticks = 0;
318 int ret;
319
320 pdata = dev_get_platdata(&pdev->dev);
321
322 info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
323 GFP_KERNEL);
324 if (!info)
325 return -ENOMEM;
326 info->irq = platform_get_irq(pdev, 0);
327 if (info->irq < 0) {
328 dev_err(&pdev->dev, "No IRQ resource!\n");
329 return info->irq;
330 }
331
332 info->chip = chip;
333 info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
334 info->dev = &pdev->dev;
335 dev_set_drvdata(&pdev->dev, info);
336
337 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
338 rtc_update_handler, IRQF_ONESHOT, "rtc",
339 info);
340 if (ret < 0) {
341 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
342 info->irq, ret);
343 return ret;
344 }
345
346 /* set addresses of 32-bit base value for RTC time */
347 pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
348 pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
349 pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
350 pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
351
352 ret = pm860x_rtc_read_time(&pdev->dev, &tm);
353 if (ret < 0) {
354 dev_err(&pdev->dev, "Failed to read initial time.\n");
355 return ret;
356 }
357 if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
358 tm.tm_year = 70;
359 tm.tm_mon = 0;
360 tm.tm_mday = 1;
361 tm.tm_hour = 0;
362 tm.tm_min = 0;
363 tm.tm_sec = 0;
364 ret = pm860x_rtc_set_time(&pdev->dev, &tm);
365 if (ret < 0) {
366 dev_err(&pdev->dev, "Failed to set initial time.\n");
367 return ret;
368 }
369 }
370 rtc_tm_to_time(&tm, &ticks);
371 if (pm860x_rtc_dt_init(pdev, info)) {
372 if (pdata && pdata->sync) {
373 pdata->sync(ticks);
374 info->sync = pdata->sync;
375 }
376 }
377
378 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc",
379 &pm860x_rtc_ops, THIS_MODULE);
380 ret = PTR_ERR(info->rtc_dev);
381 if (IS_ERR(info->rtc_dev)) {
382 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
383 return ret;
384 }
385
386 /*
387 * enable internal XO instead of internal 3.25MHz clock since it can
388 * free running in PMIC power-down state.
389 */
390 pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
391
392 #ifdef VRTC_CALIBRATION
393 /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
394 if (pm860x_rtc_dt_init(pdev, info)) {
395 if (pdata && pdata->vrtc)
396 info->vrtc = pdata->vrtc & 0x3;
397 else
398 info->vrtc = 1;
399 }
400 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
401
402 /* calibrate VRTC */
403 INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
404 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
405 #endif /* VRTC_CALIBRATION */
406
407 device_init_wakeup(&pdev->dev, 1);
408
409 return 0;
410 }
411
412 static int pm860x_rtc_remove(struct platform_device *pdev)
413 {
414 struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
415
416 #ifdef VRTC_CALIBRATION
417 flush_scheduled_work();
418 /* disable measurement */
419 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
420 #endif /* VRTC_CALIBRATION */
421
422 return 0;
423 }
424
425 #ifdef CONFIG_PM_SLEEP
426 static int pm860x_rtc_suspend(struct device *dev)
427 {
428 struct platform_device *pdev = to_platform_device(dev);
429 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
430
431 if (device_may_wakeup(dev))
432 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
433 return 0;
434 }
435 static int pm860x_rtc_resume(struct device *dev)
436 {
437 struct platform_device *pdev = to_platform_device(dev);
438 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
439
440 if (device_may_wakeup(dev))
441 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
442 return 0;
443 }
444 #endif
445
446 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
447
448 static struct platform_driver pm860x_rtc_driver = {
449 .driver = {
450 .name = "88pm860x-rtc",
451 .pm = &pm860x_rtc_pm_ops,
452 },
453 .probe = pm860x_rtc_probe,
454 .remove = pm860x_rtc_remove,
455 };
456
457 module_platform_driver(pm860x_rtc_driver);
458
459 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
460 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
461 MODULE_LICENSE("GPL");